One hundred and fifty years ago America was bigger than anyone had ever expected. The plains were bigger, the prairies were bigger, and as they neared the Civil War, even the politics were bigger. Everywhere Americans looked, they seemed to find the biggest and often the best. They found the biggest gold strike in California, the biggest mountain range in the Rockies, the biggest trees, the biggest canyon, and the biggest cactus. Yes, they found the biggest cacti in the world.

When the pioneers crossed the great Sonoran Desert of the Southwest looking for a southern route to the California goldfields, they came face to face with the biggest cacti any of them had ever seen. True, many had never seen any type of cactus before, but amidst the sparse vegetation and dwarf trees of a miserly land these exotic plants stood forty to fifty feet tall, had arms like an octopus praying for rain, and lived where there

didn’t seem to be enough water to keep even the grass growing. They were amazing and the people were amazed, writing back home about these “giant cactuses” and that name stuck for a while. They had met the saguaro, carnegiea giganta, and many of the very ones they stared at and scratched their heads over are still alive a century and a half later.

Like their tall redwood neighbors to the northwest and their ancient turtle neighbors on islands to the southwest, saguaros are very long lived. With claims of exceptional individuals being almost 250 years old, scientists say their average life span is just over 150 years. At two years old the fledgling plant is often less than ¼ inch tall. By time they reach one foot tall they’ve been around fifteen years. As they reach twenty feet tall they are between 60 and 75 years old. It is in these years that they sprout their first arms. They will keep sprouting new arms every two to three years and grow to heights taller than five story buildings. Once the symbolic sentinels of a strange frontier saguaros have endured, keeping their majesty while making a place for themselves in the modern neighborhoods and cities that have grown up around them.

One in 275 Thousand

Although there are tens of thousands of them on the hills of the Southwest, the mature saguaro is actually very rare, but not from a lack of trying. A mature plant will produce up to a hundred fruit per year on the crowns of its many arms-some have more than fifty. Each of the fruit produces in the neighborhood of 2000 seeds. So, in the century of a saguaro’s mature years, a lone cactus can produce in excess of 20 million seeds. Of those millions of seeds fewer than ten plants will reach adulthood. Experts estimate that only one in 275,000 seeds reach maturity.

However, the saguaros keep trying and that’s a good thing. Saguaros and their cactus cousins make up some of the most intense localized ecologies in the arid southwest deserts. Cactus seeds provide one of the main staples in the diets of desert animals such as wood rats, voles, kangaroo rats, jack rabbits, and other rodents, while the fruit and blossoms also feed birds like the white-winged dove, Gila woodpeckers, and curve-billed thrashers; long-nosed bats, insects including bees, and lizards such as chuckwallas, southwest geckos, and skinks. Each blossom which lasts just one day produces 1/6th of an ounce of nectar or 125 bee trips, for those who count such things. However, some modern research indicates that most, if not all, of the pollination of giant saguaros is done by the lesser long-nosed bats-an endangered species-since the blossoms open nocturnally and the bats get there first. It seems that in the strangeness of the desert, the early bird is a bat.

Humans also get nourishment from the saguaro. Native American tribes such as the Pima use the fruit for preserves and as a side dish. The Papago add winemaking to the uses of the green giants. Though not as popular as prickly pear, in its season-the fruit ripens in June and July, with the blossoms first opening on balmy April nights-the astute shopper can find saguaro candy in Boothill boutiques and gift shops in south and south-central Arizona.

In addition to supplying food, saguaros provide homes. Three applications of their unique structure make this possible. Saguaros are made of long, vertical ribs surrounded by a spongy pulp and an elastic skin. These ribs form ridges along which a row of thorns grow to protect it from larger predators. The thorns, called spines, are gray with a pinkish tint and grow in clusters of 15-30 per areole. Smaller spines surround longer ones that can reach three inches in length.

With these ridges, the trunk and arms are like bellows that expand and contract with the availability of water. When there’s very little water, the plant actually folds in exposing less surface area to the evaporating rays of the searing desert sun. When the lightning flashes and the desert sends a squall to fill the arroyos and washes, the giant saguaros swell as they drink up as many as 235 gallons of water and double their girths from just one summer monsoon season. Scientists from the Carnegie Institute of Washington Desert Laboratory calculated the weight of a giant that had fallen in Sabino Canyon outside of Tucson, Arizona in 1915 at nine tons. Soaking up these huge quantities of water is accomplished by an expansive superficial root system that can extend up to an acre.

The first inhabitants to get their homes from saguaros are birds such as the White-wing Dove which anchors its nests to the spines between close-set arms, living in typical bird fashion. Not so traditional are the Gila Woodpecker and the Gilded Flicker which excavate holes in the soft pulp between the ridges of the saguaro. The cactus responds to the invasion by excreting a glue-like resin that dries into a hard cast lining the holes. These nests, called castings, have been found to be up to 25 degrees cooler during the day and 15 degrees warmer during the night, thereby, taking the edge off the harsh temperature variations of the desert. The woodpeckers excavate new holes every season, and their abandoned castings are taken over by desert opportunists such as cactus wrens and Elf Owls. The use of saguaros as nesting sites is so important to desert fowl that the ranges of the White-wing Dove and the Elf Owl are identical to the distribution of the saguaro.

The third use of the saguaro happens after the giant plant has died. The ribs cure as trees do and provide a flexible, woody building material that is used by Native Americans for roofing and wall making materials, furniture, and tools. Survivalists suggest making a bed by piling stones, suspending saguaro ribs between them, and draping ones bedding across them. The claim is that when its done well this raises the desert camper above the scorpions. Let’s hope its done well.

Prickly Politics

The saguaros’ defense mechanisms for dealing with drought and intrusive neighbors brought them successfully into to twentieth century. Once there the saguaro faced new threats. First, over-grazing threatened to destroy every new generation. Cattle ate the small young cacti and the sheltering plants around them. During their first ten years of life saguaros are very small, under one foot tall, do not look like cacti, and are sensitive to the sun. The plants that survive are those that are sheltered by large rocks, tall grass or sheltering plants such as mesquite and Palo Verde trees and even other cacti.

The second threat was from the expansion of human communities and the construction that went with it. Cacti were simply torn down and thrown away. Small cacti were graded under and paved over. Roads and underground utilities damaged and destroyed root systems. Today saguaros are protected by federal and state laws in Arizona and California. President Hoover set aside 53,669 acres just west of Tucson, Arizona as the Saguaro National Monument in 1933. This park is still open to the public and sits adjacent to the Organ Pipe National Forest, another cactus reserve.

When state protection started it was in the form of regulation. Just as the state of Arizona regulates foresting, it regulated the harvesting of saguaros for landscaping. In the 1970’s a twenty feet tall adult saguaro could bring $1000 in markets such as San Francisco. By 1978 there were nearly twenty large scale poaching operations and proceeds from cactus theft reached a million dollars a year. Almost twenty thousand giants were poached in 1977, with another sixty thousand harvested legally. Arizona became stricter with enforcement, making the stealing and selling of saguaros carry a $1000 fine and up to a year in prison.

With city ordinances and building codes also protecting native flora, developers regularly building around the majestic giants, and their own survival mechanisms firmly in place, the saguaros will continue to cast a long shadow across the desert floor.

Saguaros have found themselves in the path of progress many times (top photo).

Building codes and state laws save saguaros such as this one as they get new neighbors (bottom photo).

This saguaro seems to be purposefully contradicting the sign for the Turkey Track Pit north of Phoenix, Arizona.

Commuters are common among the cacti (top photo).

A small bird watches from its lofty perch second arm from the right (bottom photo).